<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        let age = 21;
        // 模板字符串 外面`` 里面${变量名}
        document.write(`我今年${age}岁了`);
        document.write('<br>');

        let name = prompt('请输入您的姓名:')
        age = prompt('请输入您的年龄:')
        document.write(`我叫${name}, 今年${age}岁了`);
    </script>

</body>

</html>